search for: nagu

...am using randomForests for a classification problem. The predict function in the randomForest library, when asked to return the probabilities, has precision of two digits after the decimal. I need at least four digits of precision for the predicted probabilities. How do I achieve this? Thank you, Nagu

Hi, I am trying to run randomForests on a datasets of size 500000X650 and R pops up memory allocation error. Are there any better ways to deal with large datasets in R, for example, Splus had something like bigData library. Thank you, Nagu

...s) I am sure that some of you came across such data. How did you deal with it? Linear regressions are good for the data like y = x + 0.01Normal(mu,sigma2) i.e. a small noise (data observed in a lab). But linear regressions are bad for large noise, like typical market (or survey) data. Thank you, Nagu

...Error in predict.randomForest(fit.EBA.OM.rf.50, x.OM, type = "prob") : New factor levels not present in the training data I have about 630 predictor variables in the dataset x.OM (25 factor variables and the remaining are continuous variables). Any ideas on how to trace it? Thank you, Nagu

I need to get more digits in predicting a test sample with a random forests object. Format or options(digits=) do nothing. Any ideas? Thank you, Nagu

...r performance the model. My confusion arises from how to define these weights. If I say, classwt = c(3,6,9,1,2,3), how exactly the levels get weighted. If this is a 6X6 matrix, I can put a number in each cell to adjust the weights. How does classwt option work? Thank you in advance for any ideas. Nagu

...am wondering if there is any literature or any prior implementations of cluster analysis for only nominal (categorical) variables for a large dataset, apprx 20,000 rows with 15 variables. I came across one or two such implementations, but they seem to assume certain data distributions. Thank you, Nagu

...Y and the simple arithmetic operations (+, -, *, / etc) and some transformations (like sin, cos, exp) as input and evaluates a final expression of Y = f(X). Is there any such algorithm or a related one in R? I welcome your comments and any such references to existing algorithms in R. Thank you, Nagu

...execution, etc. or some progress bar that gets updated as a particular model is going through various steps in the optimization. Is anything like this already exists that can be just loaded in to R and use it or we have to tweak the original source of the given model to do this for me? Thank you, Nagu